The Woman was first seen in a church in conventional human clothes. She told Wilfred Mott of the church's past. It had been a convent that was attacked by "a demon from the skies" in the 1300s, and was saved by a "sainted physician". She directed Wilfred's attention to a stained glass window that contained an image of the Doctor's TARDIS. After suggesting that the physician would appear again, she vanished.
She next appeared to Wilfred Mott on Christmas Day, appearing on television during the Queen's Christmas speech. Only Wilf could see her. The Woman told Wilf that he needed to take up arms, and that the Tenth Doctor's life could still be saved. Before vanishing again, she warned Wilf not to tell the Doctor anything she had said to him.
She once more appeared to Wilf on the Vinvocci's spaceship. Wilf claimed to be lost. She appeared and said he was found. She told him that this was the Doctor's final battle, and he had to take up arms. He asked her who she was. She replied that she was lost so long ago, and vanished once more.
Each time the Woman appeared to Wilf, she appeared older, and her hair was greyer.
During the final phases of the Last Great Time War, when the Doctor had turned against the Time Lords, she, with another unnamed Time Lord, opposed Lord President Rassilon's plan to destroy Time itself. Rassilon condemned her and the other Time Lord to stand behind him in the Panopticon and cover their faces "as monuments of their shame, like the Weeping Angels of old".
When Rassilon and his retinue came to Earth on Christmas Day, 2009, the Tenth Doctor's gaze fell on her and she briefly uncovered her face and looked at him. They seemed to recognise each other. She shed a single tear, and glanced toward the White-Point Star, a crucial link in Rassilon's plan to return to reality. This seemed to be the inspiration which the Doctor needed to shoot the diamond, sending her and the other Time Lords back into the Last Great Time War. Her action saved him from the terrible choice of having to shoot either the Master or Rassilon. When the enraged Rassilon turned to kill the Doctor, she returned to her weeping position. The Doctor was saved by the Master. The link was broken, and the Woman and the other Time Lords were returned to the time lock with Gallifrey.
Although the Doctor did not reply, he did look at Donna Noble in her wedding dress. This suggests that somehow Donna Noble gets sent into the time war and remains a Time Lord, becoming the true unknown force behind the converging timeline
Behind the scenes
- In the final script, the identity of the Woman is not revealed. In a March 2009 email reprinted in REF: Doctor Who: The Writer's Tale - The Final Chapter, on pages 622-623, Russell T Davies states that he created the character as the Doctor's mother, and that this is what actress Claire Bloom was told when she was cast. During filming, newspapers The Daily Mail and The Daily Telegraph announced that Claire Bloom would be portraying the Doctor's mother.
- However, Davies has acknowledged that the character could be interpreted as any trustworthy Time Lady like Susan Foreman, Susan's mother (the Doctor's daughter or daughter-in-law) or Romana.
- In Davies' script, when Wilf asks the Doctor, "That woman. Who was she?", the stage direction reads: "The Doctor just looks. At Wilf. At Sylvia. At Donna, in the distance. Friends, mothers, brides. He's not saying." 
- Julie Gardner was of the opinion that the Woman was the Doctor's mother, but admitted there was enough ambiguity to allow other interpretations. Davies generally refused to be drawn in by Gardner's comparative certainty about the Woman's identity. (PCOM: The End of Time, Part 2)